A lithium secondary battery is an example of non-aqueous electrolyte secondary batteries. The lithium secondary battery is a secondary battery capable of charging and discharging electricity by allowing lithium ions in a non-aqueous electrolyte solution to move between a positive electrode and a negative electrode that absorb and emit lithium ions.
Patent Literature 1 discloses a technique related to a non aqueous electrolyte secondary battery having excellent battery characteristics such as storage characteristics and output characteristics. The non-aqueous electrolyte secondary battery disclosed in Patent Literature 1 includes a positive electrode including a positive-electrode active material, a negative electrode including a negative-electrode active material, and a non-aqueous electrolyte solution. The non-aqueous electrolyte solution contains lithium salt having an oxalate complex as an anion, and acetonitrile. The content of acetonitrile is 0.6 mass % to 1.0 mass % with respect to the content of lithium salt having an oxalate complex as an anion.